Grinding machine



Nov. 19, 1929; A. H. DIERKER 1,736,394

GRINDING MACHINE Filed April :1 5l 1929 Patented Nov. 19, 1929 UNITED STATES PATENT OFFICE ARTHUR H. DIERKKER, OF COLUMBUS, OHIO GRINDING MACHINE Application filed April 15, 1929. Serial No. 355,151.

treatment may be continuously introduced into and removed from the shell of the appliance. The device may also be used as a batch mill as well as one of a continuous nature.

It is another object of the invention to provide a mixer or grinder which comprises generally a rotatable shell of cylindrical form into which the materials to be treated are led and to provide within the shell a roll of smaller diameter than the internal diameter of the shell and wherein the roll is so mounted and constructed as to provide for an efficient rubbing or kneading effect on the materials under treatment to the end of bringing such materials, upon the rotation of the shell, into effective engagement with one another and 1n repeated contact to provide either a thorough mixing, rubbing, lneading or reduction action.

It is another object of the invention to construct the roll so that it is of shorter length than the material receiving chamber of the shell and also'to mount the roll within the shell in a substantially fixed position, this fixed position being Varied to suit the material being treated, whereby during the rotation of the shell the materials under process of mixing or reduction travel in cyclic paths, first, between the inner wall of the shell and the outer peripheral wall of the roll, second, into intimate Contact with other individual particles of the material or materials under treatment, and third, are permitted to return to a normal or starting position by moving past the ends of the roll and drop sing to the bottom of the shell, wherein the materials again work upwardly between the shell and l the roll to repeat the cycle.

' its action on molding sands.

The operation of this mill is best shown by In making a synthetic molding sand, quartz sand of .a suitable grain size is mixed with a plastlc vbonding material and then subjected to a kneading and rubbing action which coats each grain with a proper amount of plastic, co-

hesive material to form an aggregate of a plastic, refractory nature suitable for malring molds for metal castings. The mill or mixer comprising the present invention, gives the necessary mixing and kneading action for the making of these sands. After continued use, the bonding material in molding' sands loses its plastic nature and becomes an undesirable encrustation. on the quartz grains. In the reclaiming of foundry sands,

it is necessary to loosen this encrusted material from the grains without crushing the grains themselves. This loosening is best accomplished by a rubbing and lrneading action such as is provided by the mill hereinafter described.

For a further understanding of the invention reference is to be had to the following description and the accompanying drawings, wherein: Y

Figure l is a View in end elevation of the continuous mixing or grinding machine comprising the present invention;

Figure 2 is a side elevation thereof;

Figure 3 is a vertical longitudinal sectional view taken through the machine on the line 3-3 of Figure l;

Figure 4 is a diagrammatical view illustrating the action of a loosely mounted roll in a rotating shell, and

Figure 5 is a similar View illustrating the action of a positively positioned roll.

Referring'more particularly to the drawings, the numeral l designates my improved mixing or grinding machine in its entirety. In its preferred form the machine comprises a base 2 provided with spaced upstanding webs 3 employed to support rollers 4l arranged to serve as a cradle for the reception of a rotatable cylinder or shell 5. The ends of the cylinder are equipped with annular rails 6 which engage with the flanged wheels or rollers 4 in order to provide for the anti-fric tion support and rotation of the cylinder. Fixed to the cylinder and surrounding the same at a position between the annularI rails is a gear 7 which is adapted to engage with a pinion (not shown) driven by a suitable source of power for effecting rotation of the cylinder about its longitudinal axis.

The cylinder is closed at one end by a stationary head 8 provided with an enlarged axial opening 9, the opposite end of the cylinder being closed by a similar head 10 which also includes an arial opening 11 and is provided with a flanged lip 12. Materials are preferably introduced into the shell or cylinder by way et the opening 9 and are discharged through the opening 11.

Pivotally mounted, as at 13, upon each end of the base 2 are bell crank levers 14. 'llo the arms 14a or these levers there are secured the opposite ends of a longitudinally extending shaft 15 which passes through the cylinder 5 in a position eccentric to the axis oi' said cylinder. lVithin the cylinder the shatt 15 is provided with fixed spaced arms 18, carrying at their outer ends a longitudinally entending shalt section 1'? around which is journaled tor rotation a roll 18. Similarly there is mounted on the shalt 15 a lengi"udinal quill or sleeve 19 which carries lined lengt tudinally spaced arms 29 corresponding in function to the arms 16. Vl'he outer ends ci' the arms 2O carry a shalt section 21 which receives a roll 22, similar in function and position to the roll 18. The rolls 18 and are spaced longitudinally in the cylinder or shell 5, the interior of the latter being provided with an annular partition 23 which divides the shell into primary and secondary compartments 24 and 25 respectively. IThe partition 23 is formed with an adjustable door 26 permitting the materials released from the compartment 24 to pass into the compartment 25 and after being treated in said latter compartment the materials are discharged from the machine by way of the outlet chute 27.

To maintain the rolls 18 and 22 in the desired operating positions the shaft 15 and the sleeve 19 at a point exterior of the cylinder 5 are equipped with lined arms 28. The outer ends ot these arms are slotted to receive upstanding bolts 29 carried by the base 2. Siu1n` rounding the bolts 29 positioned by the ends of the arms 28 and the base 2 are coil springs 30. These springs normally serve to maintain the arms 28 in engagement with nuts or other stop devices 31 carried by the upper ends of the bolts 29, thus positively position ing the rolls 18 and 22 in desired positions within the shell. However, if the roll should encounter materials ot excessive thickness relief is provided through the medium of the springs`30 which operate to allow limited relief movement of the rolls. Also by means ci the threaded adjustments 32 of the springs 30 the intensity o'tl action on the materials may be determined. Furthermore, the springs 30 serve to maintain the rolls in positive engagement with the materials under treatment in the shell but in spaced relation from the walls of the cylinder 5. The shorter arms of the bell cranks 14 are formed with transversely projecting bolts 33 which operate in arcuate slots 34 provided in the sides oi' the base 2 and which operate as guides or braces in suspending the rolls in their desired positions ot operation in the shell. It desired the roll 22 in the primary compartment 24 may be formed with cleats 35 for breaking down lumpy materials or large lumps that would not ordinarily be reduced between the smooth walls o't' the roll and shell.

ln operation, the materials to be treated, for example foundry sands, are continously introduced into the primary compartment 24 et the cylinder. The operation of the ma` chine on such materials has been shown diagramniatieally in Figure V5 wherein it will be observed that due to the length oi the roll 22 and its position in the shell, the sand will 'follow the paths of movement indicated by the continuous arrow A. The position of the material being treated is secured by the rotation ot' the cylinder or shell in the direction indicated by the arrow B and due to itrictional contact between the walls of the cylinder and the loose material positioned therein, the said materials are located in the main to one side of a vertical plane passing through the axis of the cylinder. As the cylinder revolves these materials then follow the paths of movement indicated at A, being irst moved upwardly between the roll 22 and the walls ot the cylinder and then after passing said roll the material moves upwardly` to a limited extent but is returned to the bottom ont the cylinder by gravitating downwardly past the end or ends of the roll 22. This produces a continuous action of a rubbing, reducing or mixing character on the materials undergoing treatment, and this action may then be repeated as the materials pass into the secondary compartment 25 wherein they receive similar treatment lthrough the provision of the roll 18, and

from the secondary chamber the materials are discharged in a linished condition from the machine.

It the rolls 18 and 22 were not iiXed, as shown in Figure 5, but were loosely mounted in said cylinder, as shown in Figure 4, the materials undergoing treatment would have a tendency to bunch or collect on one side of the roll indicated at C in Figure 4, thus reducing the eiiiciency of the machine. However, 1 have found that by definitely positioning the rolls, as shown in Figure 5, and by using a roll of smaller length than the chamber or compartment in which it is situated for operation, a greatly improved reducing or mixing action is obtained and a machine ,a5

the'number used being dependent on the type and amount of Work required on the particular material being treated.

What is claimed is:

l. In a machine of the character described, a base, a cylinder mounted for rotation about its longitudinal axis and supported by said base, said cylinder having material receiving and discharging openings formed in the opposite ends thereof, a shaft passing through said cylinder and supported by said base, a pair of arms fixed to said shaft, and a roll rotatably carried by the outer ends of said arms and arranged immediately contiguous to one of the Walls of said cylinder.

2. In a machine of the character described,

its longitudinal axis and supported by said base, a supporting member carried by said base and arranged Within said cylinder, a roll carried by the outer portion of said supporting member and disposed immediately adjacent to the inner Wall of said cylinder, and means normally serving to maintain said roll and its supporting member Within a pref determined position Within said cylinder.

3. In a machine of the character described, a base, a cylinder mounted for rotation about its longitudinal axis and supported by said base, a pair of pivoted levers carried by said base and arranged at the opposite ends of said cylinder, a shaft carried by said levers and extending longitudinally through said cylinder, a pair of arms fixed to said shaftl and disposed Within said cylinder, a roll roand positioned immediately adjacent to the inner Wall of said cylinder, and spring means cooperative With said shaft for maintaining said roll in a predetermined position Within said cylinder.

4:. In a machine of the character described, a base, a cylinder having the opposite ends thereof provided With material receiving and discharging openings, means carried by said base for effecting the rotatable support of said cylinder' thereon, a pair of levers carried by said base, a shaft connected With the outer ends of said levers and extending longitudinally through said cylinder, arms fixed to said shaft in longitudinally spaced order and arranged Within said cylinder, a roll carried by the outer ends of said arms and disposed immediately adjacent to the inner Wall of said cylinder, another arm fixed to said shaft exteriorly of said cylinder, and spring means cooperating With said last named arm and serving to maintain said roll in a predetermined region of operation Within said cylinder'.

5. In a machine of the character described, a base, an open ended cylinder mounted for rotation about its longitudinal axis and supported by said base, a pair of levers pivotally mounted on said base and disposed at the opposite ends of said cylinder, a shaft carried by the outer ends of Vsaid levers and arranged l to extendlongitudinally through said cylinder, spaced supports fixed to said shaft, rolls 6. In a machine of the character described,

ya base, a cylinder mounted 'for rotation about its longitudinal axis and supported by said base, a supporting member carried by said base and arranged Within said cylinder, a roll Y carried by the outer portion of said'supporta base, a cylinder mounted for rotation about ing member and disposed immediately adjacent to the inner Wall of said cylinder, and yieldable means for maintaining said roll in pressure contact With the material under treatment. i

7. In a machine of the character described, a base, an open ended cylinder mounted for rotation about its longitudinal axis and supported by said base, a pair of levers pivotally mounted on said base and disposedr at t-he 0pposite ends of said cylinder, a shaft carried by the outer ends of said levers and arranged to extend longitudinally through said cylinder,` spacedV supports fixed to said shaft, a roll carried by and journaled for rotation atthe outer ends of said supports, said rolls being arranged immediately contiguous to the side Walls of said cylinder, adjustable means formed With said base and levers for maintaining the latter in various adjusted positions, yieldable means for maintaining said `rollin pressure contact with the material under treatment, and means for` effecting the adjustment of said yieldable means.

8. In a machine of the class described, a

said bell cranks, spaced supports carried by i said shaft, a roll carried by said supports and arranged immediately contiguous to the side Walls of said cylinder, an arm fixed to said shaft exteriorly of said cylinder, and spring means connecting said arm and base and serving to maintain said roll in pressure contact With the material under treatment.

9. In a machine of the character described, a base, a cylinder mounted for rotation about its longitudinal axis and supported by said base, aV pair of levers pivotally and adjustably carried by said base, said levers being arranged at the opposite ends of said cylinder, a shaft carried by and journaled in the upper ends of said levers, a pair of arms fixed to said shaft, a Aroll rotatably carried by the outer ends of said arm, asleeve carried by said shaft, a pair of arms fixed to said sleeve, a roll carried by the outer ends of said arm, and spring means cooperating With said shaft and sleeve for maintaining said rollin pressure contact With the material under treatment, the spring means co-operating With the shaft being independent from the spring means co-operating with said sleeve.

l0. In a machine of the character described, a base, an open ended cylinder mounted ior rotation about its longitudinal aXis and supported by said base, said cylinder being di vided into two chambers by a transversely arranged partition, said partition being formed with an opening for the passage of the material from one chamber to the other, a pair of levers carried by said base and situated at the opposite ends of said cylinder, a shai't carried by the outer ends of said levers and arrangedv to extend longitudinally through said cylinder, spaced sets of supports carried by said shaft, rolls carried by the outer ends of said supports and arrangedone in each of said chambers, said rolls being disposed immediately adjacent to the inner Wall of said cylinder and having their ends spaced from the end Walls of said chambers, and means (3o-operating With said rolls 'for 1nain taining the latter in pressure contact With the material under treatment.

ll. In a machine of the character described, a base, a cylinder mounted for rotation on said base, said cylinder having material receiving and discharging openings formed in the opposite ends thereof, a transversely arranged partition Within said cylinder for dividing the latter into a pair of chambers, means formed with said partition for positively advancing the material from one chamber to the other, a shaft passing through said cylinder and supported by said base, spaced sets of supports carried by said shaft, rolls carried by the outer ends of said supports and arranged one in each of said chambers, and pressure means for maintaining said rolls in predetermined regions of operation `Within said cylinder.

In testimony whereof I a'IiiX my signature.

ARTHUR H. DIERKER. 

